1. Technical Field
The present invention relates to an ultrasonic module, an ultrasonic apparatus, and a method of controlling the ultrasonic module.
2. Related Art
In the past, there has been known an ultrasonic apparatus for generating an internal tomographic image of an object such as a living body by receiving the ultrasonic wave reflected by the inside of the object. In such an ultrasonic apparatus, in recent years, in order to miniaturize the device, there is used a switching power supply as a power supply for supplying a receiving circuit of the ultrasonic wave with electrical power.
However, since the switching power supply performs switching at a high rate with semiconductor elements, high frequency noise (switching noise) easily occurs. If the switching noise is mixed in when processing a signal, which has been received in the ultrasonic element, with the receiving circuit, artifacts occur in the image.
To cope with the above, there has been proposed a configuration of suppressing an influence of the switching noise of the switching power supply (see, e.g., JP-A-2012-65694 (Document 1) and JP-A-2014-83155 (Document 2)).
In the ultrasonic apparatus described in Document 1, transmission and reception of the ultrasonic wave are performed while shifting the timing of each of the transmission and the reception of the ultrasonic wave for obtaining a plurality of echo signals obtained from the same scan line with respect to the switching timing (phase) of the switching power supply. Thus, in the case of performing a phasing addition process on each of the signals, the switching noise is prevented from overlapping each other in the same phase to suppress an increase in the artifacts to the internal tomographic image (B mode image).
Further, in the ultrasonic apparatus described in Document 2, an increase in the artifacts is suppressed by making the plurality of switching power supplies operate with respective switching cycles different from each other to thereby disperse the switching noise.
Incidentally, in the related art configuration described in Document 1 and Document 2 described above, although the artifacts are decreased by dispersing the switching noise, the switching noise itself does not decrease. Therefore, granular artifacts remain partially in some cases, and there is a problem that the artifacts cannot sufficiently be decreased and the measurement result high in accuracy cannot be obtained.